a := x + y  // generate flags
	if z == 0 { // create basic block that does not clobber flags
		return a
	}
	if a > 0 { // use flags in different basic block
		return y
	}
	return x
}

func f2(x, y float64, z int) float64 {
	a := x - y  // generate flags
	if z == 0 { // create basic block that does not clobber flags
		return a
	}
	if a > 0 { // use flags in different basic block
		return y
	}

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Test that float -> integer conversion doesn't clobber
// flags.

package main

//go:noinline
func f(x, y float64, a, b *bool, r *int64) {
	*a = x < y    // set flags
	*r = int64(x) // clobber flags
	*b = x == y   // use flags
}

func main() {
	var a, b bool
	var r int64
	f(1, 1, &a, &b, &r)
	if a || !b {

// clobber generates code to clobber pointer slots in all dead variables
// (those not marked in live). Clobbering instructions are added to the end
// of b.Values.
func clobber(lv *liveness, b *ssa.Block, live bitvec.BitVec) {
	for i, n := range lv.vars {
		if !live.Get(int32(i)) && !n.Addrtaken() && !n.OpenDeferSlot() && !n.IsOutputParamHeapAddr() {
			// Don't clobber stack objects (address-taken). They are
			// tracked dynamically.

package codegen

type T [2]*int // contain pointer, not SSA-able (so locals are not registerized)

var p1, p2, p3 T

func F() {
	// 3735936685 is 0xdeaddead. On ARM64 R27 is REGTMP.
	// clobber x, y at entry. not clobber z (stack object).
	// amd64:`MOVL\t\$3735936685, command-line-arguments\.x`, `MOVL\t\$3735936685, command-line-arguments\.y`, -`MOVL\t\$3735936685, command-line-arguments\.z`

	np uintptr
	x  [1023]int
}

var G int

//go:noinline
func clobber() {
	G++
}

func ABC(i, j int) int {
	r := 0

	// here v2 and v3 can be overlapped.
	clobber()
	if i < 101 {
		var v2 Vanilla
		v2.x[i] = j
		r += v2.x[j]
	}
	if j != 303 {
		var v3 Vanilla2
		v3.x[i] = j
		r += v3.x[j]
	}
	clobber()

	// not an overlap candidate (only one var of this size).
	var s Single

// SIGSEGV, and our runtime.sigtramp don't even know we
// are in external code, and will continue to use R10,
// this might as well result in another SIGSEGV.
// Note: both functions will clobber R0 and R11 and
// can be called from 5c ABI code.

// On android, runtime.tls_g is a normal variable.
// TLS offset is computed in x_cgo_inittls.
#ifdef GOOS_android
#define TLSG_IS_VARIABLE
#endif

	// Go to deferreturn after the panic below.
	defer func() {
		recover()
	}()

	// This call collects the heap-allocated version of x (oops!)
	runtime.GC()

	// Allocate that same object again and clobber it.
	y := new([20]byte)
	for i := 0; i < 20; i++ {
		y[i] = 99
	}
	// Make sure y is heap allocated.
	sink = y

	panic(nil)

	// After the recover we reach the deferreturn, which

//go:build (mips64 || mips64le) && gc

#include "textflag.h"

#define SYNC	WORD $0xf

TEXT ·RewindAndSetgid(SB),NOSPLIT|NOFRAME,$0-0
	// Rewind stack pointer so anything that happens on the stack
	// will clobber the test pattern created by the caller
	ADDV	$(1024*8), R29

	// Ask signaller to setgid
	MOVW	$1, R1
	SYNC
	MOVW	R1, ·Baton(SB)
	SYNC

	// Wait for setgid completion
loop:
	SYNC

// combined with any other conversions.
func f_ssa() *[8]uint {
	// Make x a uintptr pointing to where a points.
	var x uintptr
	if always {
		x = uintptr(unsafe.Pointer(a))
	} else {
		x = 0
	}
	// Clobber the global pointer. The only live ref
	// to the allocated object is now x.
	a = nil

	// Convert to pointer so it should hold
	// the object live across GC call.
	p := unsafe.Pointer(x)

	// Call gc.

//go:build (amd64 || amd64p32) && gc

#include "textflag.h"

TEXT ·RewindAndSetgid(SB),NOSPLIT,$0-0
	// Rewind stack pointer so anything that happens on the stack
	// will clobber the test pattern created by the caller
	ADDQ	$(1024 * 8), SP

	// Ask signaller to setgid
	MOVL	$1, ·Baton(SB)

	// Wait for setgid completion
loop:
	PAUSE
	MOVL	·Baton(SB), AX
	CMPL	AX, $0
	JNE	loop